Not needed since aee2d8e120
And was never really working I guess (race..)
Also, during normal initial history sync, it caused the verifier to request
proofs multiple times.
this is a performance optimisation.
measurements using a large wallet with 11k txns:
syncing XPUB for the first time takes 10 seconds. leaving window open, and
syncing same XPUB again in new window takes 30 seconds. in third window,
it takes ~50 seconds. then ~70s. presumably scaling linearly.
this is due to the history_list.update_item call being CPU-heavy.
now all of them take 10 seconds.
blockchain.read_header is expensive. do cheap tests first
on a wallet with 11k txns, that is synced except for spv proofs,
finishing sync now takes 80 sec instead of 180 sec
related: 41e088693d
If our guess of a txn getting confirmed at the same height in the new chain
as it was at in the old chain is incorrect, there is a race between the
verifier and the synchronizer. If the verifier wins, the exception will cause
us to disconnect.
Comment is no longer relevant. Also, actually it was incorrect.
Each txn is only downloaded once, though 'added' multiple times to the wallet.
The triggers are only sent out by the Synchronizer, once, when downloaded.
The actual reason for the inconsistency was that get_wallet_delta can only
give complete results once the wallet is synced.
this is a bugfix: the old code always tried to connect the chunk to
network.blockchain(). the correct behaviour is to connect to the
blockchain of the interface.
fixes race between verifier and block header download.
scenario: client starts, connects to server. while client was offline,
there was a reorg. txn A was not mined in the old chain, but is mined
after reorg. client subscribes to addresses and starts downloading headers,
concurrently. server tells client txn A is mined at height H >= reorg height.
client sees it has block header at height H, asks for SPV proof for txn A.
but the header the client has is still the old one, the verifier was faster
than the block header download (race...). client receives proof. proof is
incorrect for old header. client disconnects.
SomberNight
ThomasV